
Preheat waffle iron according to manufacturer's instructions.
In a large bowl, beat eggs, milk, melted butter, and vanilla extract until well combined.
Add buckwheat flour, sugar, baking powder, and salt, stir until just combined. Small lumps are okay, don't overmix. Let batter rest for 5 minutes to thicken slightly.
Lightly grease the waffle iron with cooking spray or butter. Pour an appropriate amount of batter onto the waffle iron (amount varies by waffle maker size).
Close lid and cook for 4–5 minutes, or until steam stops and waffles are golden brown and crisp. Remove carefully and repeat with the remaining batter.
Serve warm with maple syrup, fresh fruit, butter, or whipped cream.